JP2009233644A - Apparatus and method for precipitation removal of scale component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable retarding of the acidification of cooling water by efficiently removing the chlorine generated in the cooling water without using a complicated control system, while removing scale components reliably. <P>SOLUTION: This apparatus 100 for the precipitation removal of the scale components includes: electrodes 120; an electrolyzer 110 for removing the scale components by passing water to be treated containing the dissolved scale components therethrough and electrolyzing the water to be treated to precipitate the scale components on the surface of the electrodes 120; and a chlorine removing section 130 disposed downstream of the electrodes 120 for removing the chlorine contained in the water to be treated by aerating the water to be treated having passed through the electrodes 120. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a scale component precipitation removing apparatus and a scale component precipitation removing method used for a circulating cooling water system or the like.

  Circulating cooling water systems are widely used for cooling in district heating and cooling (DHC) and cooling equipment in substations. Circulation type cooling water system is a technology to repeatedly use as cooling water by evaporating a part of the cooling water whose temperature has risen because the object to be cooled is cooled, and lowering the temperature of the remaining cooling water by the heat of vaporization accompanying this. It is.

  In general, industrial water and tap water (tap water) are used as cooling water. In a circulating cooling water system, industrial water and tap water (tap water) are used to supplement the amount of water vaporized to cool the cooling water. Is replenished.

  Industrial water and clean water contain hardness components (scale components) such as calcium (Ca), magnesium (Mg), and silica (Si), so they are included in the remaining cooling water as the cooling water evaporates. The hardness component is concentrated and deposited as a scale (precipitate). If scale deposits inside the piping or inside the equipment, the equipment may break down due to a decrease in flow rate or deterioration in thermal conductivity.

  Conventionally, in order to prevent the occurrence of scale, there is a technique for reducing the hardness component concentration of cooling water by adding a large amount of makeup water and discharging (blowing) a part of the concentrated cooling water into sewage. However, there was a cost for discharging a large amount of makeup water and sewage.

  In addition, a technique for adding a chemical for preventing precipitation of scale components to cooling water has been developed. However, when draining the cooling water containing the medicine, it is necessary to perform a separate treatment in order to reduce the influence on the environment, resulting in high costs.

In view of this, a technique is disclosed in which cooling water in a circulating cooling water system is passed through an electrolyzer and a scale component contained in the cooling water is deposited on the electrode surface to be removed (for example, Patent Documents 1 and 2). In the above-described electrolysis apparatus, the cooling water is electrolyzed as shown in the following reaction formula 1 and reaction formula 2, chlorine (Cl ₂ ) is generated at the anode (anode), and hydroxide ions (OH) are generated at the cathode (cathode). ^- ) Is generated.

The hydroxide ions (OH ⁻ ) generated at the cathode are combined with calcium ions (Ca ²⁺ ) and magnesium ions (Mg ²⁺ ), which are scale components contained in the cooling water (Reaction Formula 3, Reaction Formula 4 and Reaction). By formula (5), calcium carbonate (CaCO ₃ ), magnesium hydroxide (Mg (OH) ₂ ), and magnesium silicide (Mg ₃ Si ₄ O ₁₀ (OH) ₂ ) having extremely low solubility are precipitated and precipitated.

  By removing the precipitate (precipitate) of the scale component generated as described above with drainage or the like, the scale component is prevented from depositing inside the piping or equipment other than the electrolytic device.

On the other hand, the chlorine generated at the anode reacts with water (see Reaction Formula 6 and Reaction Formula 7), thereby generating hypochlorous acid (HClO) and protons (H ⁺ ). Furthermore, hypochlorous acid is ionized into hypochlorite ions (ClO ⁻ ) and protons (H ⁺ ) in water.

  As described above, since hypochlorous acid, which is an oxide, is generated at the anode, the cooling water can be sterilized.

However, the concentration of hypochlorous acid and protons increases at the anode as electrolysis is performed to deposit scale components at the cathode. Therefore, the pH of the cooling water is lowered, that is, the cooling water becomes acidic, and there is a possibility that the pipes and equipment are corroded. Further, when the concentration of residual chlorine (Cl ₂ ) in the cooling water increases, the increase in chlorine ions (Cl ⁻ ) destroys the metal passive film, which may cause local corrosion of piping and equipment.

Therefore, in Patent Document 1, the amount of chlorine generated can be controlled by controlling the current density using the fact that the generation rate of chlorine is proportional to the current density applied to the electrode.
JP 2006-98003 A JP 2007-90267 A

  In the technique described in Patent Document 1, it is necessary to control the current density with high accuracy in order to maintain the residual chlorine concentration at a predetermined value. However, in practice, it is difficult to control the current density according to the quality of the cooling water that changes sequentially, and in order to achieve this, there is a problem that equipment costs increase, such as arranging multiple measuring instruments. There was a point.

  Further, once a problem occurs in the control of the current density, the amount of chlorine generated increases, the risk of equipment corrosion increases, and there is a problem in equipment safety. In particular, in DHC and the like, since it is necessary to continuously process a large amount of cooling water for 24 hours, equipment damage due to corrosion of pipes and equipment is not allowed.

  Therefore, in view of the above-described problems of the conventional technology for removing scale components, the present invention efficiently removes chlorine generated in cooling water without using a complicated control system while reliably removing scale components. An object of the present invention is to provide a scale component precipitation removal apparatus and a scale component precipitation removal method capable of delaying the acidification of cooling water.

  In order to solve the above-mentioned problem, a representative configuration of a scale component precipitation removing apparatus according to the present invention includes an electrode, and passes the water to be treated containing the dissolved scale component and electrolyzes the scale. An electrolyzer that removes the components by precipitating them on the surface of the electrode; and a chlorine removing unit that removes chlorine contained in the water to be treated by aeration of the water to be treated that has passed through the electrode downstream of the electrode; It is characterized by providing.

  As described above, the chlorine gas is mixed in the electrolyzed water to be treated, and eventually reacts with the water and dissolves. However, according to the above configuration, by removing aeration of the water to be treated that has passed through the electrodes, the chlorine generated as a result of electrolyzing the water to be treated can be removed without reacting with the water without providing a complicated control system. Can do. Therefore, the generated chlorine can be prevented from dissolving in the water to be treated and becoming hypochlorous acid, and the pH of the water to be treated can be prevented from being lowered (acidity being raised). At the same time, an increase in residual chlorine concentration in water can be suppressed.

  In addition, chlorine is generated above the dissolution equilibrium concentration by electrolysis. In the conventional scale component deposition and removal apparatus, the water to be treated after electrolysis circulates immediately, so the chlorine gas contained in the water to be treated cannot be volatilized and is ionized in the water to be treated. The acidity of water increases (see Reaction Scheme 6 and Reaction Scheme 7). However, since the water to be treated immediately after passing through the electrode is aerated by the above configuration, chlorine can be removed from the water to be treated faster than the ionization reaction rate of chlorine.

  The chlorine removing unit may include a pumping unit that pumps up the water to be treated downstream of the electrode, and an air aeration unit that sprinkles or sprays the pumped water to be treated in the air.

  Chlorine present in water volatilizes in the air by touching (aeration) the air. With the configuration including the pumping unit, chlorine immediately after generation, that is, water to be treated immediately downstream of the electrode is pumped up, and the water to be treated is pumped up by the air aeration unit, so that chlorine can be efficiently removed.

  Moreover, since the area (surface area) where the to-be-processed water is exposed to air can be increased by the configuration in which the to-be-treated water is sprayed by the air aeration unit, chlorine can be volatilized into the air more efficiently. .

  The air aeration unit may sprinkle or spray the treated water pumped up on a treatment tank provided on the downstream side of the electrode.

  Since the pumped water to be treated is sprinkled or sprayed into the treatment tank, it is not mixed with the water to be treated containing chlorine, and chlorine can be efficiently removed from the water to be treated.

  The chlorine removal section includes an overflow section composed of a partition wall that forms a treatment tank on the downstream side of the electrode, and the overflow section may be dropped into the treatment tank while aeration of the water to be treated using a drop. Good.

  Thereby, even if it does not have a pumping-up part, to-be-processed water can be efficiently aerated using a head.

  The chlorine removing unit may include a bubbling unit that feeds bubbles into the water to be treated downstream of the electrode.

  Similarly to the configuration having the pumping unit and the watering treatment unit described above, chlorine can be volatilized into the bubbles by exposing the water to be treated to the supplied bubbles. Moreover, since the area (surface area) to which the to-be-processed water is exposed to the bubbles can be increased as the bubbles supplied from the bubbling unit are smaller, chlorine can be more efficiently vaporized into the air.

  The bubbling part may be arranged in a processing tank provided on the downstream side of the electrode.

  Since the bubbling portion is arranged in the treatment tank, it is not mixed with the water to be treated containing chlorine, and the chlorine can be efficiently removed from the water to be treated.

  In addition, it is possible to prevent a decrease in the electrolysis rate due to the bubbles fed by the bubbling unit coming into contact with the electrodes.

The current applied to the electrodes constituting the electrolyzer is preferably a current density of 0.5 mA / cm ² to 5 mA / cm ² .

  Thereby, a scale component can be deposited efficiently. In particular, Ca can be precipitated efficiently.

The water flow may be performed at 0 cm / sec to 100 cm / sec. Since the residence time of hydroxide ions (OH ⁻ ) generated from the electrode (cathode) after electrolysis is shortened at 100 cm / sec or more, scale ions such as calcium ions (Ca ²⁺ ) and magnesium (Mg ²⁺ ) ions The bond rate of hydroxide ions (OH ⁻ ) decreases and the precipitation rate of scale components decreases.

  In order to solve the above-described problems, a representative configuration of the method for removing and depositing scale components according to the present invention is to perform treatment by passing water to be treated containing dissolved scale components through an electrolysis apparatus having electrodes. A method for depositing and removing a scale component that deposits and removes the scale component on the electrode surface, wherein the water to be treated that has passed through the electrode is aerated downstream of the electrode to remove chlorine contained in the water to be treated. It is characterized by.

  The components based on the technical idea of the scale component precipitation removing apparatus described above and the description thereof are also applicable to the scale component precipitation removing method.

  As described above, according to the scale component precipitation removing apparatus and the scale component precipitation removing method of the present invention, the chlorine generated in the cooling water can be efficiently removed without using a complicated control system while reliably removing the scale component. By removing it well, it becomes possible to delay the acidification of the cooling water.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

(1st Embodiment: Scale component precipitation removal apparatus 100)
FIG. 1 is an explanatory diagram for explaining a scale component precipitation removing apparatus 100 according to the present embodiment. In particular, FIG. 1A is a diagram for explaining a place where the pumping unit pumps up the water to be treated, and FIGS. 1B and 1C show the scale component precipitation removing apparatus 100 according to the present embodiment. FIG.

  As shown in FIG. 1, the scale component precipitation removal apparatus 100 includes a treated water inlet 102, a treated water outlet 106, a flow rate adjusting unit 104, an electrolyzer 110, a chlorine removing unit 130, and a treatment tank 150. And comprising.

  To-be-treated water that has flowed in from the to-be-treated water inlet 102 is electrolyzed by the electrolyzer 110, passes through the treatment tank 150, flows out from the to-be-treated water outlet 104, and is recycled.

  The flow rate adjusting unit 104 adjusts the flow rate of the water to be treated that flows into the electrolyzer 110 from the water inlet 102 to be treated.

  The electrolysis device 110 includes an electrode 120 and a current control unit 126.

  The electrode 120 includes an anode 122 and a cathode 124. In the present embodiment, platinum, titanium, and oxide can be suitably used for the anode 122, and stainless steel can be suitably used for the cathode 124.

  FIG. 2 is an explanatory diagram for explaining precipitation of scale components contained in water to be treated by electrolysis using the electrolyzer 110 according to the present embodiment.

As shown in FIG. 2, chlorine (Cl ₂ ) is generated at the anode 122 in the electrolyzer 110, and carbon dioxide, which is a precipitate of calcium ions (Ca ²⁺ ) and magnesium ions (Mg ²⁺ ) as scale components, at the cathode 124. Calcium (CaCO ₃ ) and magnesium hydroxide (Mg (OH) ₂ ) will precipitate.

  The current control unit 126 supplies current to the electrode 120 to electrolyze (electrolyze) the water to be treated.

  FIG. 3 is an explanatory diagram for explaining the relationship between the current density and the precipitation amount of the scale component (FIG. 3A) and the relationship between the flow rate of the water to be treated and the precipitation amount of the scale component (FIG. 3B). is there. In FIG. 3, in order to obtain the optimum values of the current density and the flow rate of the water to be treated, the electrolyzer 110 that does not include the chlorine removing unit 130 and the treatment tank 150 is used.

In FIG. 3A, the current density was changed by fixing the flow rate of the water to be treated to 4.5 cm / sec. As a result, as shown in FIG. 3A, it was found that when the current density was about ² mA / cm ² , the largest amount of scale component was precipitated.

In FIG. 3B, the current density was fixed at ² mA / cm ² and the flow rate of the water to be treated was changed. As a result, as shown in FIG. 3 (b), it was found that when the flow rate of the water to be treated was 4.5 cm / sec, the largest amount of scale component was precipitated. If it is less than about 4.5 cm / sec, the residence time of the liquid to be treated after electrolysis becomes longer, so the electrolysis efficiency is considered to decrease. On the other hand, since the residence time of hydroxide ions (OH ⁻ ) generated from the electrode (cathode) after electrolysis is shortened at about 4.5 cm / sec or more, calcium ions (Ca ²⁺ ) and magnesium ( It is considered that the bonding rate between Mg ²⁺ ) ions and hydroxide ions (OH ⁻ ) decreases and the deposition rate of scale components decreases.

Therefore, when the current density applied to the electrode 120 by the electric control unit is about ² mA / cm ² and the flow rate of the water to be treated that is passed through the electrolyzer 110 is about 4.5 cm / sec, the most scale component Can be efficiently deposited.

  The chlorine removing unit 130 includes a pumping unit 132 and an air aeration unit 134.

  The pumping unit 132 pumps up the water to be treated downstream of the electrode 120. As shown in FIG. 1A, in the present embodiment, the pumping unit 132 arranges the pumping port 132 a near the downstream 122 a of the anode 122 to pump up the water to be treated. Thereby, the to-be-processed water containing the chlorine immediately after generate | occur | producing in the anode 122 can be pumped up efficiently.

When chlorine dissolves in water, it produces hypochlorous acid (HClO) and protons (H ⁺ ). Furthermore, hypochlorous acid is ionized into hypochlorite ions (ClO ⁻ ) and protons (H ⁺ ) in water. Therefore, when chlorine is dissolved in water, the pH of the water is lowered. However, as described above, the pumping unit 132 efficiently pumps the water to be treated containing chlorine immediately after being generated at the anode 122, that is, the water to be treated containing chlorine before being dissolved in the water. Can be minimized.

  The air aeration unit 134 may be configured by a nozzle 134a (see FIG. 1B) or a spray unit 134b (see FIG. 1C). As shown in FIGS. 1B and 1C, the air aeration unit 134 aerates the air by sprinkling or spraying the water to be treated pumped up by the pumping unit 132. Chlorine contained in water volatilizes in the air by aeration with air (touching air). Therefore, the chlorine contained in the water to be treated can be efficiently vaporized by aeration of the water to be treated containing chlorine immediately after being generated at the anode 122 pumped up by the pumping unit 132.

  In particular, in the air aeration unit 134 configured by the spray unit 134b, it is possible to increase the area (surface area) where the water to be treated is exposed to the air, so that chlorine can be more efficiently vaporized into the air. .

  Moreover, in this embodiment, the air aeration part 134 sprinkles or sprays the to-be-processed water pumped from the pumping part 132 to the processing tank 150 provided downstream from the electrolyzer 110 and separated from the electrolyzer 110.

  Thereby, the to-be-processed water before electrolysis will not mix with the to-be-processed water containing chlorine, and chlorine can be efficiently removed from the to-be-processed water.

  In the present embodiment, a dropping unit 152 is provided above the processing tank 150 and below the air aeration unit 134. Thereby, since the to-be-processed water sprayed (sprayed) from the air aeration part 134 can be dripped, air aeration can be performed further.

(Scale component precipitation removal method)
Next, a scale component precipitation removal method using the scale component precipitation removal apparatus 100 will be described. FIG. 4 is a flowchart showing the flow of the scale component precipitation removing method according to the present embodiment.

  First, water to be treated containing dissolved scale components is passed through an electrolyzer 110 having an electrode 120 (S160) and electrolyzed (S162). The treated water electrolyzed in S162 is pumped to the pumping unit 132 (S164), and the treated water pumped in S164 is sprinkled or sprayed by the air aeration unit 134 and aerated (S166).

[Comparison with comparative example]
Next, the scale component precipitation removing apparatus 10 having a conventional configuration and the scale component precipitation removing apparatus 100 according to the present embodiment will be described in comparison. FIG. 5 is a diagram for explaining the comparison between the embodiment and the comparative example. In particular, FIG. 5A is an explanatory diagram of the scale component precipitation removing device 10 having a conventional configuration, and FIG. 5B is a conventional configuration. The figure which shows the pH change obtained as a result of conducting the experiment which passed water to be treated using the system imitating scale component precipitation removing apparatus 10 or the system imitating scale component precipitation removing apparatus 100 is shown. Yes.

  As shown in FIG. 5, in the case where treated water (pH 8.2) is treated (water flow) using the scale component precipitation removing apparatus 100 according to the present embodiment, the treated water after 12 hours of operation is The pH was 6.9. On the other hand, when water to be treated (pH 8.2) is treated (water flow) using a conventional scale component precipitation removing apparatus that does not have the chlorine removing unit 130, the water to be treated after 12 hours of operation has a pH of 6. It became four.

As described above, when the water to be treated is electrolyzed, chlorine is generated from the anode. When chlorine dissolves in water, it produces hypochlorous acid (HClO) and protons (H ⁺ ). Furthermore, hypochlorous acid is ionized into hypochlorite ions (ClO ⁻ ) and protons (H ⁺ ) in water. Therefore, when chlorine is dissolved in water, the pH of the water is lowered.

  However, the structure having the chlorine removing unit 130 can efficiently volatilize chlorine in the air before being dissolved in water, and prevent the pH of the water to be treated from being lowered (the acidity is increased). Can do. Therefore, it becomes possible to reduce corrosion of piping and equipment.

  Further, as a result of examining the residual chlorine concentration, the residual chlorine concentration of the treated water after 12 hours of operation in the conventional scale component precipitation removing apparatus 10 was 7.4 ppm, whereas the scale component precipitation removal apparatus 100 The residual chlorine concentration of the water to be treated after 12 hours of operation was 0.3 ppm or less. This sufficiently satisfies the cooling water quality standard of the water quality guidelines for refrigeration and air conditioning equipment (JRA-GL-1994).

  On the other hand, the current efficiency (%), which is the number of moles of precipitation per passing electric quantity (F), was 66.8% when the water to be treated was passed through the conventional scale component precipitation removing apparatus 10. When the water was passed through the scale component precipitation removing apparatus 100, it was 52.4%.

(Second Embodiment: Scale Component Precipitation Removal Device 200)
In the above-described first embodiment, the chlorine removing unit having the pumping unit and the air aeration unit has been described. However, the water to be treated can be aerated even without the pumping unit. In the second embodiment, the scale component precipitation removing apparatus will be described. Note that components having substantially the same functions as those of the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.

  FIG. 6 is an explanatory diagram for explaining the scale component precipitation removing apparatus 200 according to the present embodiment. As shown in FIG. 6, the scale component precipitation removing device 200 includes a treated water inlet 102, a treated water outlet 106, a flow rate adjusting unit 104, an electrolyzer 110, and a chlorine removing unit 230. Composed.

  In the present embodiment, the chlorine removing unit 230 includes an overflow portion 232 and a bubbling portion 234.

  The overflow section 232 includes a partition wall that forms a treatment tank 250 on the downstream side of the electrode 120, and dams the water to be treated to the electrolyzer 110. When the water to be treated is stored in the electrolyzer 110 at a height equal to or higher than the overflow portion 232, it flows down to the downstream of the overflow portion 232. The water to be treated falls while being aerated with air by a drop provided by the overflow section 232. By providing the overflow part 232 in this way, air can be aerated using the head even if the pumping part 132 is not provided. Therefore, the power for pumping up the treated water is not required, and chlorine can be efficiently removed from the treated water.

  The bubbling part 234 is installed downstream of the overflow part 232, that is, at the lower part of the treatment tank 250 formed by the overflow part 232, and supplies bubbles (air) into the water to be treated.

  Therefore, chlorine can be volatilized into the bubbles by exposing the water to be treated to the supplied bubbles. In addition, the more and the smaller the bubbles that the bubbling unit 234 feeds, the more the area (surface area) of the water to be treated exposed to the bubbles can be increased. Can do.

  Further, with the configuration in which the bubbling unit 234 is arranged in the treatment tank 250, the bubbling unit 234 is not mixed with the water to be treated containing chlorine, and the chlorine can be efficiently removed from the water to be treated. Furthermore, it is possible to prevent a decrease in the electrolysis rate due to the bubbles fed by the bubbling unit 234 coming into contact with the electrodes.

  The bubbling unit 234 is not necessarily used in combination with the overflow unit 232, and the bubbling unit 234 is further provided in the scale component precipitation removing apparatus 100 having the pumping unit 132 and the air aeration unit 134 according to the first embodiment. The chlorine may be removed more efficiently. Further, the scale component precipitation removing apparatus 200 according to the present embodiment may include the dropping unit 152.

(Third embodiment)
In 1st Embodiment and 2nd Embodiment mentioned above, although the structure of 2 tanks which have the electrolyzer 110 and the processing tanks 150 and 250 was demonstrated, it is also possible to set it as the structure which does not have the processing tanks 150 and 250. . In this embodiment, the scale component precipitation removing apparatus will be described. In addition, about the component which is substantially the same function as 1st Embodiment and 2nd Embodiment mentioned above, the same code | symbol is attached | subjected and description is abbreviate | omitted.

FIGS. 7A to 7E are explanatory views for explaining the scale component precipitation removing apparatus 300 (300a to 300e) according to the present embodiment.
The scale component precipitation removing apparatus 300 (300a to 300e) includes a treated water inlet 102, a treated water outlet 106, a flow rate adjusting unit 104, an electrolyzing device 110, and a chlorine removing unit 130. The

  In the scale component precipitation removing apparatus 300a shown in FIG. 7A, a part of water to be treated downstream of the electrode 120 (anode 122) is pumped up by the pumping unit 132, and an air aeration unit 134 composed of the nozzle 134a pumps up. Water is sprinkled further downstream of the mouth 132a, and the water to be treated is aerated.

  In the scale component deposition / removal device 300b shown in FIG. 7B, a part of water to be treated downstream of the electrode 120 (anode 122) is pumped up by the pumping unit 132, and an air aeration unit 134 composed of a spraying unit 134b is used. The water to be treated is sprayed further downstream of the pumping port 132a to aerate the water to be treated.

  The scale component precipitation removing device 300c shown in FIG. 7C further includes a water reservoir 352, and a pumping unit 132 pumps up part of the water to be treated downstream of the electrode 120 (anode 122). The air aeration unit 134 is sprayed on the water reservoir 352 to aerate the water to be treated. The treated water that has been aerated with air passes through the water reservoir 352 and merges with the treated water that has not been pumped downstream of the pumping port 132a.

  The scale component precipitation removing device 300d shown in FIG. 7D further includes a water reservoir 352 and a water flow part 354, and the pumping part 132 pumps up part of the water to be treated downstream of the electrode 120 (anode 122). The air aeration unit 134 configured by the spray unit 134b sprays the water reservoir 352 to aerate the water to be treated. The water to be treated which has been aerated and stored in the water reservoir 352 passes through the water passage 354 and joins with the water to be treated which has not been pumped downstream of the water outlet 106 to be treated.

  In the scale component precipitation removing apparatus 300e shown in FIG. 7 (e), a part of water to be treated downstream of the electrode 120 (anode 122) is pumped up by the pumping unit 132, and an air aeration unit 134 constituted by a spraying unit 134b is used. The water to be treated is aerated by spraying upstream of the electrode 120.

  Similar to the scale component precipitation removing devices 100 and 200 described above, the scale component precipitation removing device 300 is configured to include the chlorine removing unit 130 and removes chlorine by aeration of the water to be treated that has passed through the electrode. Therefore, chlorine produced as a result of electrolyzing the water to be treated can be removed without providing a complicated control system. In addition, since the treated water that has been aerated with air is returned to the electrolyzer 110 without disturbing the flow rate of the treatment liquid in the electrolyzer 110, the optimum flow rate of the treated water can be maintained, and a reduction in treatment efficiency is prevented. Is possible. Therefore, the generated chlorine can be prevented from dissolving in the water to be treated and becoming hypochlorous acid, and the pH of the water to be treated can be prevented from being lowered (acidity being raised).

  Although the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such examples. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  For example, in the third embodiment described above, the configuration including the chlorine removing unit 130 has been described, but a configuration including the bubbling unit 234 can also be suitably used.

  Note that each step in the scale component precipitation removal method of the present specification does not necessarily have to be processed in time series in the order described in the flowchart, and may include processing in parallel or by a subroutine.

  The present invention can be used for a scale component precipitation removing apparatus and a scale component precipitation removing method.

It is explanatory drawing for demonstrating the scale component precipitation removal apparatus concerning 1st Embodiment. It is explanatory drawing for demonstrating precipitation of the scale component contained in the to-be-processed water by the electrolysis using the electrolyzer concerning 1st Embodiment. It is explanatory drawing for demonstrating the relationship between the current density and the precipitation amount of a scale component, and the relationship between the flow rate of to-be-processed water and the precipitation amount of a scale component. It is the flowchart which showed the flow of the scale component precipitation removal method concerning 1st Embodiment. It is a figure explaining comparison of an embodiment and a comparative example. It is explanatory drawing for demonstrating the scale component precipitation removal apparatus concerning 2nd Embodiment. It is explanatory drawing for demonstrating the scale component precipitation removal apparatus concerning 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Conventional scale precipitation removal apparatus, 100, 200, 300 ... Scale component precipitation removal apparatus, 102 ... Processed water inflow port, 104 ... Flow rate adjustment part, 106 ... Processed water outlet, 110 ... Electrolyzer, 120 ... Electrode , 122 ... anode, 122a ... near the downstream of the anode, 124 ... cathode, 126 ... current control unit, 130, 230 ... chlorine removal unit, 132 ... pumping unit, 132a ... pumping port, 134 ... air aeration unit, 134a ... nozzle , 134b ... spraying part, 150 ... treatment tank, 152 ... dropping part, 200 ... scale component precipitation removing device, 232 ... overflow part, 234 ... bubbling part, 250 ... treatment tank, 352 ... water reservoir, 354 ... water flow Part

Claims (9)

An electrolysis apparatus having an electrode and removing the scale component by depositing it on the surface of the electrode by electrolyzing the treated water containing the dissolved scale component through water;
A chlorine removing unit that removes chlorine contained in the water to be treated by aeration of the water to be treated that has passed through the electrode downstream of the electrode;
A scale component precipitation removing apparatus comprising: The chlorine removing unit is
A pumping unit that pumps up the water to be treated downstream of the electrode;
An air aeration unit for sprinkling or spraying the pumped water to be treated in the air;
The scale component precipitation removing apparatus according to claim 1, comprising:   3. The scale component precipitation removing apparatus according to claim 2, wherein the air aeration unit sprays or sprays the pumped water to be treated on a treatment tank provided on the downstream side of the electrode. The chlorine removing unit is
Including an overflow section comprising a partition wall forming a treatment tank on the downstream side of the electrode;
The overflow section is
The scale component precipitation removing apparatus according to claim 1, wherein the water to be treated is dropped into the treatment tank by aeration using a head. The chlorine removing unit is
The scale component precipitation removing apparatus according to claim 1, further comprising a bubbling unit that feeds bubbles into the water to be treated downstream of the electrode.   6. The scale component precipitation removing apparatus according to claim 5, wherein the bubbling unit is disposed in a treatment tank provided on the downstream side of the electrode. The scale composition analysis according to any one of claims 1 to 6, wherein the current applied to the electrodes constituting the electrolyzer is a current density of 0.5 mA / cm ² to 5 mA / cm ^2. Ejection removal device.   The scale component precipitation removing apparatus according to any one of claims 1 to 7, wherein the water flow is performed at 0 cm / sec to 100 cm / sec. A scale component precipitation removing method for precipitating and removing the scale component on the electrode surface by passing the electrolyzed water containing the dissolved scale component through an electrolysis apparatus having an electrode,
Downstream of the electrode, the water to be treated that has passed through the electrode is aerated with air,
A scale component precipitation removing method, wherein chlorine contained in the water to be treated is removed.

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